Core 2 quad Q9450 overclocking help

This should be your first stop.
Core2 Overclocking Guide (generic guide based on an Asus motherboard)
http://www.tomshardware.co.uk/forum/259899-11-core-over...

For your motherboard (BIOS's tend to be different):
http://www.pcstats.com/articleview.cfm?articleid=2104&p...
Look at the second set of screen shots (the top one labeled FSB and Memory Config).

The FSB speed is 1333 MHz. That is really the stock FSB clock. Speed is 1/4 of that - 333 MHz. The nForce 600/700 BIOS is a little strange. You adjust the FSB clock, not the FSB freq.

Set memory to Linked. Once you do that, you should see Memory speed drop to 667 MHz.

The screen shot for the voltages show their maximum values. Do not go that high or you will fry something.

So. Leave your memory timing on Auto. Set memory to Linked. For 3.0 GHz, FSB speed is 375 MHz, FSB clock is 1500 MHz MHz, and memory clock will be 750 MHz.

These combinations will give you a 1:1 FSB:RAM ratio and generally the best stability. Running the RAM faster gives little extra performance in a Core2 system.

On my eVGA 680i board, running the memory Linked gave me a fair amount of instability, so I ran Unlinked and manually entered memory settings to let me run 1:1.

Keep the CPU core voltage under 1.45 volts and your load temps under 70 C. Do not exceed 2.2 volts RAM voltage.